Sections of hypocotyls, roots and leaves from Pentalinon andrieuxii plantlets were transiently transformed with Agrobacterium tumefaciens LBA4404 bearing the binary plasmid pCAMBIA2301 with an interrupted β-Glucuroni...Sections of hypocotyls, roots and leaves from Pentalinon andrieuxii plantlets were transiently transformed with Agrobacterium tumefaciens LBA4404 bearing the binary plasmid pCAMBIA2301 with an interrupted β-Glucuronidase (GUS) gene. Histochemical GUS assays showed transient gene expression in all infected tissues, being older roots those which displayed the most intense GUS staining. To our knowledge, this is the first report of Pentalinon andrieuxii susceptibility to Agrobacterium tumefaciens-mediated genetic transformation.展开更多
Root-secreted phytochemicals mediate multiple interactions in the rhizosphere. The root exudation process can be altered by various biotic factors, including pathogenic and non-pathogenic microbes, and abiotic factors...Root-secreted phytochemicals mediate multiple interactions in the rhizosphere. The root exudation process can be altered by various biotic factors, including pathogenic and non-pathogenic microbes, and abiotic factors like temperature and soil moisture. It has been suggested that root secretion of specific flavonoids is influenced by diurnal rhythms （by light or dark） but a comprehensive analysis of the overall secretion of phytochemicals in response to diurnal rhythms has not been studied. In this study, we analyzed the effect of light/dark cycles on root exudation profiles using Arabidopsis as a model plant. Our results reveal that the root secretion of phytochemicals is partly regulated by the diurnal light cycle and follows two main patterns of secretion： （1） the large majority of phytochemicals in the exudates showed no diurnal pattern in their secretion, and （2） a few compounds showed a diurnal pattern in their secretion： three compounds increased in secretion only under light; two compounds increased in secretion only while it was dark; and two compounds increased in secretion during the transition from dark to light. Root-specific ABC transporters have been implicated in root exudation; an analysis of the gene expression patterns of ABC transporters in the roots of Arabidopsis at specific time points revealed that none of the ABC transporters followed a diurnal expression pattern, suggesting that they are expressed constantly during the day and night. Similarly, we analyzed the expression in roots of genes involved in secondary metabolite biosynthesis and found that some of the genes involved in phenylpropanoid and glucosinolate biosynthesis （i.e. 4-coumarate-CoA ligases （4CL1 and 4CL2）, flavonol synthases （FSl and FS2）, and CYP79B3） followed distinct diurnal expression patterns. Overall, we have discovered that while root exudation of the majority of phytochemicals is constitutive, the secretion of a few compounds follows a diurnal rhythm, which is in accordance with the expression of some genes involved in secondary metabolism.展开更多
基金financial support from the National Council for Science and Technology-Mexico(CONACYT)(Project No.59695-Z).
文摘Sections of hypocotyls, roots and leaves from Pentalinon andrieuxii plantlets were transiently transformed with Agrobacterium tumefaciens LBA4404 bearing the binary plasmid pCAMBIA2301 with an interrupted β-Glucuronidase (GUS) gene. Histochemical GUS assays showed transient gene expression in all infected tissues, being older roots those which displayed the most intense GUS staining. To our knowledge, this is the first report of Pentalinon andrieuxii susceptibility to Agrobacterium tumefaciens-mediated genetic transformation.
文摘Root-secreted phytochemicals mediate multiple interactions in the rhizosphere. The root exudation process can be altered by various biotic factors, including pathogenic and non-pathogenic microbes, and abiotic factors like temperature and soil moisture. It has been suggested that root secretion of specific flavonoids is influenced by diurnal rhythms （by light or dark） but a comprehensive analysis of the overall secretion of phytochemicals in response to diurnal rhythms has not been studied. In this study, we analyzed the effect of light/dark cycles on root exudation profiles using Arabidopsis as a model plant. Our results reveal that the root secretion of phytochemicals is partly regulated by the diurnal light cycle and follows two main patterns of secretion： （1） the large majority of phytochemicals in the exudates showed no diurnal pattern in their secretion, and （2） a few compounds showed a diurnal pattern in their secretion： three compounds increased in secretion only under light; two compounds increased in secretion only while it was dark; and two compounds increased in secretion during the transition from dark to light. Root-specific ABC transporters have been implicated in root exudation; an analysis of the gene expression patterns of ABC transporters in the roots of Arabidopsis at specific time points revealed that none of the ABC transporters followed a diurnal expression pattern, suggesting that they are expressed constantly during the day and night. Similarly, we analyzed the expression in roots of genes involved in secondary metabolite biosynthesis and found that some of the genes involved in phenylpropanoid and glucosinolate biosynthesis （i.e. 4-coumarate-CoA ligases （4CL1 and 4CL2）, flavonol synthases （FSl and FS2）, and CYP79B3） followed distinct diurnal expression patterns. Overall, we have discovered that while root exudation of the majority of phytochemicals is constitutive, the secretion of a few compounds follows a diurnal rhythm, which is in accordance with the expression of some genes involved in secondary metabolism.
